When two terrorist bombs exploded at the Boston Marathon on April 15, Stoughton Fire Capt. Bob O’Donnell and Brockton firefighter Donald Gazerro ran toward the wounded, not away from them.

On Thursday, O’Donnell and Gazerro – who were both off-duty and separately watching the race when chaos erupted that horrific day – will be recognized for their heroism at the 24th annual Firefighter of the Year Awards at MIT’s Kresge Auditorium in Cambridge.

Gazerro and O’Donnell will be among on- and off-duty firefighters from communities including Boston, Cambridge and Watertown who will receive the Fire Marshal’s Award for their heroic response to the Boston Marathon bombings and its aftermath in the days that followed.

Firefighters from communities including Norwell, Marshfield, Quincy, Scituate and Weymouth will also be honored during the ceremony.

Gazerro and O’Donnell are among those being hailed as heroes for running into the chaos and carnage near the finish line after two bombs exploded.

Gazerro, a West Bridgewater resident, was among emergency responders who knelt by bombing victims Martin Richard, 8, and Lingzi Lu, 23, to try and help them. Both died in the attacks,

Even though he knew Martin was dying, Gazerro took over chest compressions from another responder, but then a Boston EMS worker came over to the group huddled around the boy’s body and said they needed to stop.

Gazerro, who has taught emergency response techniques for more than a decade, knew he was right. In a mass-casualty incident, first responders have to prioritize even when that requires making awful decisions.

So they covered Martin’s face with a towel. His mother, who was wounded, cried out and clutched her son’s body. Another woman wrapped her in a tight embrace.

“I still think about it,” Gazerro, 47, an 18-year veteran of the Brockton Fire Department, said Sunday afternoon. “Anytime you help with a small child, you never really forget those moments. That certainly stays with you.”

O’Donnell, 56, who lives in Easton and is also an emergency department nurse at Milton Hospital, in April described a “sea of blood” when tending to people injured by the bombs. He made several tourniquets for bombing victims who suffered severed arms, legs and fingers to stop the bleeding.

Emergency responders began rolling victims onto spine-boards and searching for ambulances to take them to hospitals.

“It was awful. It was a sea of blood,” O’Donnell, who could not be reached for comment Sunday, said in April. “You’re slipping in people’s blood, and they’re hanging onto each other.”

The explosions near the marathon’s finish line that day killed three people, wounded more than 170 and reawakened fears of terrorism.

Both Gazerro and O’Donnell had gone to the Boston Marathon separately to see their sons run in the 26.2-mile race that day.

Page 2 of 2 - Instead, they were thrust into a chaotic scene of carnage and suffering. But at a moment’s notice, both men did what they were trained to do – save lives.

“I certainly appreciate (being honored), but I prefer to see any efforts to be put toward the victims and families who suffered,” Gazerro said Sunday.

In 1997, Gazerro said he was among Brockton firefighters who were recognized at the annual Firefighter of the Year Heroic Awards ceremony for saving a family from a house fire.